As synthesis reaction systems of a hydrocarbon compound which synthesize hydrocarbon compounds by a Fischer-Tropsch synthesis reaction (hereinafter referred to as “FT synthesis reaction”) by using a synthesis gas mainly composed of carbon monoxide gas (CO) and hydrogen gas (H2) as a raw material gas, for example, like the PATENT DOCUMENT 1, there is a bubble column type slurry bed FT reaction system which carries out the FT synthesis reaction by introducing the synthesis gas into a slurry in which solid catalyst particles are suspended in liquid hydrocarbons. A hydrocarbon compound synthesized by the FT synthesis reaction is mainly utilized as a raw material for liquid fuel products such as naphtha (raw gasoline), kerosene, and gas oil.
In an FT synthesis reactor provided for the conventional bubble column type slurry bed FT reaction system as described above, in order to investigate the carbon number distribution of a hydrocarbon compound synthesized inside the reactor, reaction state generated by a reaction between the slurry and a source gas, and the concentration distribution of the slurry inside the reactor, it is necessary to extract contents, in which the slurry and the source gas are mixed, from the synthesis reactor.    PATENT DOCUMENT 1: Specification of US Patent Application Publication No. 2006-0272986